22 



BACTERIAL DISEASES OF PLANTS 



FIG. 14. Bacterial black chaff of wheat. Stalk bent double to show diseased 

 (black-striped) upper part and sound (pale green) middle part. Wheat No. 268, 

 collected June 28, 1917, on the Rhodes farm at Manhattan, Kansas. Photo- 

 graphed July 3, 1917, by James F. Brewer, using a W. and W. panchromatic plate 

 and a yellow color screen. 



